Known and feared as ‘Black Mold’ stachybrotys is a common toxic mold with near worldwide distribution. A filementus fungi, the genus contains around 50 species, only some of which are toxic. It proliferates in damp or wet conditions and grows easily and quickly in and around buildings. The name stachybrotys comes from the Ancient Greek word stakhus (σταχυς) meaning ear of grain, stalk, stick and botrus (βότρυς) meaning a cluster or bunch as in grapes.
Stachybrotys was first described and named by August Carl Joseph Corda (1809–1849) the Czech physician and mycologist, who’s six volume Icones fungorum hucusque cognitorum defined his career. Both his parents died when Corda was an infant, and he was raised by his grandmother. Travelling between Berlin and Prague, Corda knew many great luminaries of his day, including the astronomer Alexander Von Humboldt, botanist Kurt Sprangel, and zoologist Martin Hinrich Lichtenstein, creator and director of the Berlin zoological gardens. He died very young at 40, returning from a collection trip to Texas.
Micrograph image of stachybrotys magnified 300x courtesy Hella Delicious, used with permission under a Creative Commons 3.0 license.
Potassium permanganate + glycerol exothermic chemical reaction
The pink/lilac flame produced in this exothermic reaction is typical of potassium salts and is a result of the potassium permanganate, a very powerful oxidising agent. The simple definition of an oxidising agent is a substance that adds molecular oxygen (O2) to a compound, something which causes an exothermic reaction. Glycerol is poured on to some potassium permanganate crystals. Initially there is a time lag as the activation energy of the reaction is reached, in this reaction the energy is provided with heat energy and temperature. The right temperature that this reaction needs to begin is roughly room temperature, making it a ‘spontaneous reaction’, (as in, it could happen at any time in a room at ‘normal room temperature’- about 20∘C). The speed and intensity of the reaction then increases as the temperature produced by the reaction raises its rate (a self-catalysing reaction, like a snowball effect).
Few things are as engaging or beautiful in the night sky as a full moon. Next time you gaze up, consider a word (acronym, really, with the strength of a word in some circles) well known to scientists at NASA: KREEP. KREEP stands for the group of elements found in a sample (along with samples collected from many other missions) retrieved by the Apollo program almost exactly 45 years ago: K stands for potassium, REE for Rare Earth Elements and P for phosphorous. Of all the lunar soil samples returned to earth (841 pounds worth!) the KREEP samples were particularly important to scientists as the combination of elements rarely occurs outside of a molten state. The KREEP sample furthered knowledge of the early formation of both Earth and the Moon, and remains a significant milestone in the understanding of Earth and lunar geology.
Black and white image courtesy Luc Viatour / www.Lucnix.be
False color image courtesy NASA:
In this image, which was mapped from Lunar Prospector, we see a global map of the element thorium, a radioactive trace element showing the location of KREEP, an important key to lunar igneous history.
Sundew Catapults Prey into Trap
Drosera glanduligera is a species of sundew, a group of carnivorous plants that use sticky tentacles to ensnare their prey. This is species is unique in that it has extremely fast ‘snap tentacles’ which literally fling their prey into their sticky traps.
Sundews have evolved the ability to digest insects as an adaptation to their nutrient poor habitats. Once a prey is caught in the glue-like secretions, it either dies from exhaustion or asphyxiates from being smothered in dew. The plant then secretes enzymes which break down the insect, allowing the plant to absorb its nutrients.
All species of sundew are able to move their inner tentacles to pass prey towards the center of the leaf, where digestion is most efficient. Many species are able to fold the surface of the leaf around the prey to ensure contact with a larger digestive surface.
Drosera glanduligera is the fastest moving sundew, with ‘snap tentacles’ which fold inwards within 75 milliseconds. This action is triggered when an insect makes contact with them, and are powerful enough to catapult the insect into the center of the leaf, where it becomes glued down.
Gif from video: Poppinga, S. Et al. via Wikimedia Commons
For teaching: plant physiology
Every Asteroid Discovered Since 1980
From the far, far away to the startlingly close, there have been over 600,000 asteroids identified in the inner solar system since 1980. This visualization tracks them all.
The video is the work of Scott Manley. Manley included the path of the near-by asteroids that have been identified starting 34 years ago and carrying on to this year. The asteroids that cross our own orbit are in red, the ones that just get close are in yellow, and the ones even further out are all in green.